Summary

• There are 4 types of ASD: ostium secundum, ostium primum, sinus venosus, and unroofed coronary sinus. Secundum defects are the most common.
• Most patients are asymptomatic. Untreated defects can produce right atrial enlargement, cardiac arrhythmias, and heart failure over time.
• Secundum, primum, and coronary sinus defects with small shunts (ratio of pulmonary flow to systemic flow, Qp:Qs, <1.5) do not require treatment. Corrective closure is required if the shunt is larger (Qp:Qs ratio ≥1.5), there is right atrial enlargement, or the patient has a sinus venosus defect.
• Corrective closure, if required, is usually performed at 2 to 4 years of age but can be performed at a younger age in symptomatic patients.
• Percutaneous device closure is the preferred treatment for secundum defects, and surgical closure is reserved for larger secundum defects, technically challenging cases, and other defects.
• If right-to-left shunting (Eisenmenger's syndrome) occurs, the ASD is operable if the shunt is reversible with pulmonary vasodilators. If the shunt is irreversible, the treatment is largely supportive.